T-Mobile’siPhone5WillFeatureHDVoiceAtLaunch

Even though T-Mobile’s iPhone 5 looks just like the handsets offered by Verizon, Sprint, and AT&T on the outside, it does have some unique attributes.
First, T-Mobile will be the only U.S. carrier to offer HD Voice technology for the iPhone 5.
Officially announced during the handset’s launch last year, the wideband audio “fills up” more of the frequency spectrum leading to clearer and crisper phone conversations. That is if you still make phone calls.
Another unique program from T-Mobile is Wi-Fi Calling. If you haven’t heard of the feature, it allows users to receive phone calls to their number using any Wi-Fi hotspot around the world. It also is a big advantage in areas with little or no coverage.
Currently, four Android phones from the carrier support the feature. At the event in New York City, Engadget asked a T-Mobile official whether Wi-Fi Calling will be supported at the launch of the handset April 12:

Here at today's T-Mobile UnCarrier event in New York City, the company's chief marketing officer Michael Sievert told me that "it's not coming" at launch, but when pressed, he confessed that T-Mob "loves its WiFi Calling feature, and I'll have to leave it at that." I then asked if it's on the roadmap, and if the company would like to have it included in an ideal world, which garnered a smile that I can safely assume means something positive for the future.

T-Mobile’s iPhone 5 will also be just a bit cheaper over time compared to purchasing a completely unlocked handset up front. With $100 down and 24 monthly payments of $20, that totals $579. When you’re done paying off the handset, it can be unlocked and taken to another carrier
Buying an unlocked 16GB iPhone 5 up front from Apple will set you back $649 right now. So, if you go with T-Mobile, you’ll save $70 and be able to make monthly payments for the phone. That’s a pretty nice deal.
Will you be snagging an iPhone 5 from T-Mobile?